The invention relates to a gas generator.
In gas generators, in particular for vehicle occupant restraint systems, it must be prevented that the igniter or the entire gas generator is charged electrostatically to such an extent that an electrostatic discharge can occur, having the consequence of an activation of the gas generator being in the installed state. For this, some solutions have been considered with incorporated so-called ESD protection elements such as capacitors, varistors or the like. The accommodating of these additional elements in the igniter is often costly, because these elements must be arranged on the connection lines so as to be protected against mechanical stress.
The invention provides a gas generator with a simple, inexpensive protection against electrostatic discharge, in which the integration into the gas generator is possible in a simple manner.
This is achieved in a gas generator which comprises a generator housing which has a base part, and an electric igniter which has a rear side, is fastened in the base part and has connection lines on the rear side. The gas generator further comprises a propellant charge in the generator housing, the propellant charge being provided outside the igniter and an insulating bush surrounding the connection lines and fastened to the generator housing. The insulating bush consists of plastic and contains electrically conductive particles. The electrically conductive particles must be contained to such an extent in the plastic and be selected such that the contact resistance of the insulating bush is sufficiently reduced, so that the electrostatic discharge does not take place directly in the igniter. Rather, through the invention, on discharge a spark shall be able to jump more easily between the short-circuiting spring possibly provided in the insulating bush (during shipping of the gas generator, without a connection plug put on) or the connection line (in the installed state of the gas generator) and the generator housing to which also the insulating bush, provided with electrically conductive particles, belongs. The electric igniter is thereby better protected from spurious releases. Additional elements to the ESD protection can thereby be dispensed with.
The connection lines are preferably pins projecting from the rear side of the igniter, which pins are surrounded by the insulating bush. The insulating bush is preferably accommodated in a recess in the gas generator housing.